Seeds of Sorrow by Elle Beaumont

Life for Eden is simple—until she's given to the nightmare king. Wishing for more adventure in her life, and hoping to escape from under her overprotective mother's thumb even for just a night, Eden accepts an invitation to a ball in another king's court. Despite her mother's ire, it all seems worth it as their travels take Eden away from home for the first time and into the middle realm. Draven, known as the king of nightmares and ruler of the dark realm, Andhera, desires only to remain in his kingdom and maintain control and order over the ravenous creatures that lurk in the shadows. However, he finds himself drawn away by the mysterious summons of his brother, who appears to need his aid desperately. In one evening, thrust unwittingly together, Lady Eden and King Draven find themselves beguiled, betrayed, and betrothed. Neither is prepared for what it means for them, or for the immortal realms. As politics and death intermingle, can two entirely different fae learn to rely on one another? Or will the dark realm destroy all that is held most innocent and precious within the realms, and Eden herself? Seeds of Sorrow is a romantic retelling of Hades & Persephone with a fae and vampire spin on it! If you love immersing yourself in dark, descriptive worlds, political intrigue and romance, you'll love this story.